Safety test tank



March 1966 E. M. JONES SAFETY TEST TANK Filed March 2, 1964 FIG.2

ERNEST M. JONES INVENTOR.

United States Patent 3,239,095 SAFETY TEST TANK Ernest M. Jones, Odessa,Tex., assignor to J. & J. Steel and Supply Co. Inc., Odessa, Tex., acorporation of Texas Filed Mar. 2, 1964, Ser. No. 348,558 3 Claims. (Cl.220-85) invention relates to accident prevention and more particularlyto sound-ing tanks in a safe manner.

In the production of petroleum, the petroleum is first moved from theground into a nearby tank. When the oil well is first completed, it isnot known whether the well will be commercial .or not. Therefore, a testtank on skids is brought to the site. The petroleum is then conducteddirectly from the well into this test tank.

To test the well, the petroleum is put into the tank, but not taken outof the tank until it is accurately gauged to determine the productionpotential of the well. The amount of oil produced for a given time isgauged by sounding the tank. I.e., a gauger ascends to the top of thetank, opens a gauging hatch, lowers a metal tape into the tank, and thusmeasures the amount of oil in the tank.

In many cases, the petroleum as produced is mixed with poisonous gases.In the past, these test tanks have often had cove-rs without vents whichproduces a slight positive pressure. When the cover of the gauging hatchis opened, the gases rush out sometimes overcoming the gauger. Sometimesthe gauger llS killed in this operation; sometimes he becomesunconscious and falls from the top of the tank to his injury.

An object of this invention is to provide a test tank for petroleumproduction which reduces the hazards to the gauger when sounding thetank.

Another object is to provide a test tank which has a closed, but ventedtop and a pipe extending under the gauging hatch so that only thosegases within the pipe are expelled to the atmosphere when the gauginghatch cover is removed and thus, only a small amount of gas is released.

A further object is to provide a safety cage for the gauger to occupywhile sounding the tank.

Still further objects are to achieve the above with a device that issturdy, durable, simple, versatile and reliable, yet inexpensive andeasy to manufacture and operate.

The specific nature of the invention as well as other objects, uses, andadvantages thereof will clearly appear from the following descriptionand from the accompanying drawing, the different views of which are notto the same scale, in which:

FIG. 1 is a perspective of a tank according to this invention.

FIG. 2 is an axial sectional view of the tank of FIG. 1.

FIG. 3 is a sectional detail of the connection of the thief pipe to theroof deck of the tank.

Referring more particularly to the drawing, it will be seen that I haveprovided a tank with a cylindrical shell 10, floor deck 12, and roofdeck 14. There is a manhole 16 and numerous openings 18 for the variousconnections which may be desired to make to the tank. Skid 20 extendsvertically up one side of the tank for moving the test tank to differentlocations. When it is desired to move the tank, the tank is tilted overonto the skid 20 and chains attached to the bar 22 at one end of theskid and the tank moved by skidding.

Thief pipe 24 is attached to the roof deck 14 as by welding. The pipe 24extends from the roof deck 14 to within a short distance (24") of thefloor deck 12. The pipe 24 contains no openings except those openings atthe bottom of the pipe and at the top of the pipe. The opening at thebottom of the pipe 24 is below what would be the normal liquid level ofthe tank. Therefore, the pipe 24 has access to gas only from the surfaceof the liquid which is within the pipe itself. The pipe 24 is imperviousto gas from top to bottom.

Gauging hatch 26 has flange 28 on the bottom thereof which is bolted tothe roof deck 14 around the top opening of the pipe 24. Cover 30 withvents 32 fits over the top of the gauging hatch 26 preventing debris orrain from falling into the hatch 26 and thus the pipe 24. Vent 34through roof deck 14, is on the opposite side of the tank from the pipe24. Ladder 36 extends vertically up the side of the tank. Cage 38 isattached to the side of the tank immediately adjacent the gauging hatch26. The cage 38 includes floor grating 40 and side railings 42. Theladder 36 terminates immediately adjacent the cage 38.

It will be understood that when the gauger ascends the ladder 36 andstands in the cage 38 that although he is not completely protected, heis rather well protected from falling from his high position should hebe overcome by fumes. Although there might be poisonous fumes beingexpelled from the vent 34, these do not cause any great diflicultyinasmuch as the vent 34 is as far away from the gauger as possible. Thefumes are well dissipated across the diameter of the tank. There isnever pressure within the pipe 24 inasmuch as the cover 30 is vented tothe atmosphere by the vents 32. The liquid level within the pipe 24 willbe the same as the liquid level in the tank itself inasmuch as theliquid in the pipe 24 will be of the same density as in the tank itself.Also, the pipe 24 is open to the atmosphere while gauging because thecover 30 is off. Also, the tank itself is at all times vented to theatmosphere by the vent 34.

Therefore, I have provide-d a structure by which the tank may be soundedwith accuracy and safety. It will be understood that if the diameter ofthe thief pipe 24 is eight inches and the diameter of the tank is thirtyfeet, that the volume of gas in the tank above the liquid will be abouttwo thousand times as great as the volume of gas within the pipe 24above the liquid. Therefore, even though some of the gas might beexhausted when the cover 30 is removed, there is only one twothousandths as much gas. The amount of gas to which the gauger isexposed is much less. Also, should the gauger be overcome, he is in theprotected cage 38 and is less likely to be injured by a fall.

The roof deck 14 is impervious to gases except for its openings whichinclude the opening 18 (generally having a connection attached thereto),the vent 34, and the ganging hatch 26. I Therefore, the gauger is onlyconcerned with the fumes from the two sources. One is through thegauging hatch 26 which is open to a relatively small volume of gas. Theother is from the vent 34 which is far enough away to not causeexcessive fumes where the gauger is.

It will be apparent that the embodiment shown is only exemplary and thatvarious modifications can be made in construction, materials, andarrangement within the scope of the invention as defined in the appendedclaims.

I claim as my invention:

1. A safety test tank comprising in combination:

(a) a she-ll with (b) a floor deck,

(0) a gas impervious roof deck,

(d) a vent in the roof deck for venting the tank to the atmosphere,

(e) a gauging hatch in the roof deck remote from said vent,

(f) said gauging hatch opening into a thief pipe,

g) said thief pipe extending gas imperviously from the gauging hatch toadjacent the bottom of the tank,

(b) said gauging hatch being vented to the atmosphere at all times sothat a gauger sounding the tank through the gauging hatch is not exposedto the gases in any portion of the tank except those gases within thethief pipe.

2. In a safety test tank having (a) a shell,

(b) a floor deck, and

(c) a roof deck,

(d) said roof deck closing the top of the tank except for the openingshereafter specified,

(e) a gauging hatch in the roof deck,

(f) a ladder attached to the shell of the tank leading to the roof deck,and

(g) a plurality of openings in the tank for making various externalconnections to the tank;

the improvement comprising in combination:

(h) a cage attached to the shell of the tank adjacent to the ladder andadjacent to the gauging hatch in which a gauger may stand while soundingthe tank,

(j) a thief pipe attached to the roof deck in communication with thegauging hatch,

(k) said pipe extending within the tank from the roof deck to adjacentto the floor deck,

(m) said pipe being open at the top and bottom,

(11) said pipe being impervious to gas between its top and bottom,

(0) a cover over said gauging hatch,

(p) said cover having vents theret-hrough so that the tank and the pipeare vented to the atmosphere,

(q) a vent in the roof deck remote from said gauging hatch; so that thetank may be sounded by lowering a tape into said thief pipe through saidgauging hatch while the gauger is standing in the cage.

3. A safety test tank comprising in combination:

(a) a cylindrical shell with (i) a floor deck and (ii) a roof deck,

(b) said roof deck impervious to gases except for the openingshereinafter enumerated.

(c) a manhole in the shell,

(-d) numerous openings in the shell,

(e) skids extending vertically up the shell for moving said test tankfrom one location to another,

(f) a gauging hatch opening through the roof deck,

(g) a thief pipe attached to the roof deck under the gauging. hatch,

(h) said pipe extending vertically within the tank to near the floordeck of the tank,

(j) said pipe impervious to gases between the top and bottom,

(k) a cover over the gauging hatch with vents therethrough,

(m) a vent in the roof deck venting the tank to atmosphere,

(11) said vent diametrically opposite to said gauging hatch,

(o) a ladder extending vertically up the shell side of the tank on theoutside thereof, and

(p) a cage on the shell adjacent the gauging hatch and adjacent theladder so that a gauger may climb the ladder and stand within the cagewhile sounding the tank by lowering a tape through the gauging hatch atwhich time the gauger will be exposed to the fumes from within said pipeonly and the fumes from the tank will be expelled from said vent whichis diametrically opposite across the roof deck from him.

References Cited by the Examiner UNITED STATES PATENTS 222,263 12/1879Fitzgerald et a1. 22085 1,736,842 11/1929 Wilcox 220--85 2,457,15512/1948 Jackson 220-85 2,576,893 11/ 1951 Stewart 22085 2,865,499 12/1958 Brogren 206 -46 2,997,878 8/ 1961 Graham 73304 FOREIGN PATENTS174,240 3/1935 Switzerland.

THERON E. CONDON, Primary Examiner.

R. H. SCHWARTZ, Assistant Examiner,

1. A SAFETY TEST TANK COMPRISING IN COMBINATION: (A) A SHELL WITH (B) AFLOOR DECK, (C) A GAS IMPERVIOUS ROOF DECK, (D) A VENT IN THE ROOF DECKFOR VENTING THE TANK TO THE ATMOSPHERE, (E) A GAUGING HATCH IN THE ROOFDECK REMOTE FROM SAID VENT, (F) SAID GAUGING HATCH OPENING INTO A THIEFPIPE, (G) SAID THIEF PIPE EXTENDING GAS IMPERVIOUSLY FROM THE GAUGINGHATCH TO ADJACENT THE BOTTOM OF THE TANK,